Increased current flow enhances the risk of organic carbon loss fromZostera marinasediments: Insights from a flume experiment

Limnology and Oceanography, Journal Year: 2018, Volume and Issue: 63(6), P. 2793 - 2805

Published: Aug. 13, 2018

Abstract Hydrodynamic processes are important for carbon storage dynamics in seagrass meadows, where periods of increased hydrodynamic activity could result erosion and the loss buried carbon. To estimate impacts on resuspension organic (C org ) seagrass‐vegetated sediments, we exposed patches (0.35 × 0.35 cm) Zostera marina (with different biomass, shoot densities, sediment properties) to gradually unidirectional (current) flow velocities ranging from low (5 cm s −1 high (26 a hydraulic flume with standardized water column height 0.12 m. We found that higher substantially (by more than threefold) proportion C suspended resulting up 5.5% ± 1.7% (mean SE) surface sediment. This was presumably due larger, carbon‐rich detritus particles. Resuspension plots correlated properties (i.e., bulk density, porosity, sedimentary plant structure belowground biomass). However, density had no influence (comparing unvegetated sediments sparse, moderate, dense bed types), which be relatively experimental setup maximum 253 shoots m −2 reflecting natural conditions Swedish west coast. The projected increase frequency intensity forces climate change thus negatively affect function meadows as sinks.

Language: Английский

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Integration of Submerged Aquatic Vegetation Motion Within Hydrodynamic Models

Water Resources Research, Journal Year: 2020, Volume and Issue: 56(8)

Published: Aug. 1, 2020

Abstract Aquatic models used for both freshwater and marine systems frequently need to account submerged aquatic vegetation (SAV) due its influence on flow water quality. Despite importance, parameterizations are generally adopted that simplify feedbacks from SAV, such as canopy properties (e.g., considering the deflected height) bulk friction coefficient. This study reports development of a fine‐scale non‐hydrostatic model demonstrates two‐way effects SAV motion interaction with flow. An object‐oriented approach is applied capture multiphase phenomena, whereby leaf‐scale based discrete element method combined dynamics resolve stresses currents waves. The verified through application laboratory‐scale seagrass bed. A force balance analysis revealed leaf elasticity buoyancy most significant components influencing horizontal vertical momentum equations, respectively. sensitivity canopy‐scale coefficients depth, current speeds, density was explored. Deeper also shown lead smaller decrease in height. can contribute improving assessment processes quality, sediment stabilization, carbon sequestration, restoration, thereby supporting an understanding how waterways coasts will respond changes brought about by changing climate.

Language: Английский

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Modeling dissolved inorganic carbon considering submerged aquatic vegetation

Ecological Modelling, Journal Year: 2020, Volume and Issue: 431, P. 109188 - 109188

Published: July 21, 2020

Language: Английский

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Seagrass Meadows Reduce Wind-Wave Driven Sediment Resuspension in a Sheltered Environment

Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 8

Published: Jan. 31, 2022

Seagrass meadows are prominent in many coastal zones worldwide and significant contributors to global primary production. The large bottom roughness (or canopy) created by seagrass substantially alters near-bed hydrodynamics sediment transport. In this study, we investigate how a meadow low-energy environment (forced local winds) modifies mean wave-driven flows assess relates suspended concentration (SSC). A two-week field study was conducted at Garden Island southwestern Australia, shallow sheltered region subjected diurnal sea-breeze cycles, typical of environments where seagrasses found. turbulent flow structure, along with optical estimates SSC, were measured within both canopy over an adjacent bare bed. Near-bed current velocities the on average 35% velocity above canopy. Oscillatory wave less attenuated than velocities, values being 83% those Mean maximum shear inferred from currents waves frequently exceeded threshold for resuspension, but no variation observed SSC. However, correlation between SSC bed stress estimated using inside When resuspended, there substantial differences SSCs layer, higher levels confined This demonstrates importance measuring hydrodynamic processes directly canopies predicting role play regulating rates resuspension.

Language: Английский

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Habitat suitability modelling to improve understanding of seagrass loss and recovery and to guide decisions in relation to coastal discharge

Marine Pollution Bulletin, Journal Year: 2022, Volume and Issue: 186, P. 114370 - 114370

Published: Nov. 29, 2022

Language: Английский

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